Abstract: Indian J Otolaryngol Head Neck Surg https://doi.org/10.1007/s12070-021-02616-7 OTHER ARTICLES Virucidal effect of povidone iodine on COVID-19 in the nasopharynx: an open-label randomized clinical trial Mostafa Kamal Arefin1 • S. K. Nurul Fattah Rumi1 • A. K. M. Nasir Uddin1 • Sultana Sahana Banu1 • Mala Khan2 • Ahsanul Kaiser3 • Joybaer Anam Chowdhury4 Md. Abdullah Saeed Khan5 • Mohammad Jahid Hasan5 • Received: 14 April 2021 / Accepted: 10 May 2021 Ó Association of Otolaryngologists of India 2021 Abstract Povidone-iodine (PVP-I) is a time-tested antiseptic agent with excellent virucidal (99.99%) properties. Repurposing it against coronavirus disease-19 (COVID-19) is a relatively newer concept and has been sparsely tested in vivo. The most common route of entry of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) is the nasopharynx. Averting colonization of the virus could be one of the best options to reduce the incidence of infection. PVP-I gargle and mouthwash were found to be effective in vitro rapid inactivation against SARS-CoV-2 on a smaller scale (Hassandarvish et al. in BDJ 1–4, 2020, Pelletier et al. in ENTJ 1–5, 2020). However, efficacy in humans is lacking. To assess the virucidal effect of PVP-I against SARS-CoV-2 located in the nasopharynx was the objective of this parallel armed randomized clinical trial. We screened all RT-PCR-confirmed COVID-19 cases aged 18 years and above with symptoms. Written informed consent was obtained before randomization. Nasopharyngeal clearance of SARS-CoV-2 was tested after single time application of PVP-I nasal irrigation (NI) at diluted concentrations of .4%, .5% and .6% and PVP-I nasal spray (NS) at diluted concentrations of .5% and .6%. All groups were compared to the corresponding controls (distilled water). The primary outcome was viral clearance in a repeat RT-PCR (qualitative), and the secondary outcome was the number of adverse events. Final data analysis was performed using the statistical software SPSS (Version 20). A total of 189 confirmed COVID-19 cases were randomized into seven groups: 27 patients in each group. Of all, 159 (84.1%) were male, and 30 (15.9%) were female. We observed a statistically significant proportion of nasopharyngeal clearance with all strengths of PVP-I NI and PVP-I NS compared to the corresponding controls. Additionally, 0.5% NI was significantly better than 0.5% NS for viral clearance (p = 0.018) and had the highest nasopharyngeal clearance among all & Mostafa Kamal Arefin arefin61dmc@gmail.com Md. Abdullah Saeed Khan abdullahdmc@gmail.com Mohammad Jahid Hasan dr.jahid61@gmail.com S. K. Nurul Fattah Rumi rumi17dr@gmail.com A. K. M. Nasir Uddin dmch@hospi.dghs.gov.bd 1 Dhaka Medical College Hospital, Dhaka, Bangladesh 2 Bangladesh Reference Institute of Chemical Measurements (BRICM), Dhaka, Bangladesh 3 Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh 4 National Institute of Cardiovascular Diseases (NICVD), Dhaka, Bangladesh 5 Pi Research Consultancy Center, Dhaka, Bangladesh Sultana Sahana Banu sultana_aus@yahoo.com Mala Khan malakhan_07@yahoo.com Ahsanul Kaiser ahsanulkaisertamal@gmail.com Joybaer Anam Chowdhury joybaer6106@yahoo.com 123 Indian J Otolaryngol Head Neck Surg Table 1 Patient Demographics, baseline clinical characteristics and virucidal activity of PVI-P Nasal spray and mouth wash Nasal irrigation (NI) p-value .4% NI .5% NI .6% NI Control-NI (CNI) .4% NI v CNI .5%..